China is the world’s largest mobile payment service market, with both tech and financial giants promoting their own tools to make easier payment for daily shopping, dining and commuting. Most big cities in China are cashless cities. Almost all vendors of products and services accept mobile payments. Many government agencies such as traffic authorities and hospitals have also joined the mobile payment party. Mobile payment has become a common feature throughout users’ daily lives. 3. The world’s largest mobile payment service market is ____________, most cities of which are ____________ cities.